Which action best demonstrates a school leader monitoring instructional practices and student progress to prepare all students for a challenging curriculum?

The action of comparing student performance on tests and grades is the best demonstration of a school leader monitoring instructional practices and student progress. This approach enables a comprehensive analysis of how well students are grasping the curriculum and identifies any gaps in understanding. By looking at both tests and grades, a leader can gain insights into different aspects of student learning, such as mastery of content and the effectiveness of instructional methodologies.

This monitoring is essential for understanding trends in student progress and making informed decisions about instructional strategies, resource allocation, and interventions for students who may need additional support. It allows for proactive measures to be taken to prepare all students for a more challenging curriculum, ensuring that their educational needs are being met.

The other options, while beneficial for specific contexts, do not provide the same breadth of insight into overall student performance and instructional effectiveness as the comparison of tests and grades.